In development of a plant for water supply and sewerage or the like, a control logic diagram that describes an operation plan defining an operation specification of a facility by a flowchart and a logical operation is often used. However, depending on scale of the plant to develop, several hundred control logic diagrams are needed in some cases, and it is desired to reduce the number of necessary control logic diagrams by efficiently creating the control logic diagrams.
For example, in a case disclosed in Patent Document 1, by using logical connection information or positional information about a signal or a logical element in a control logic diagram, it is possible to retrieve, about logic described in a certain control logic drawing, similar logic included in another control logic diagram. Accordingly, by converting frequently described logic into a component, it becomes possible to reduce the number of necessary control logic diagrams.